design/designer-form/src/main/java/com/fr/design/mainframe/FormSpacingLineDrawer.java

package com.fr.design.mainframe;

import com.fr.design.designer.creator.XChartEditor;
import com.fr.design.designer.creator.XCreator;
import com.fr.design.designer.creator.XCreatorUtils;
import com.fr.design.designer.creator.XElementCase;
import com.fr.design.designer.creator.XLayoutContainer;
import com.fr.design.designer.creator.XWParameterLayout;
import com.fr.design.form.parameter.FormParaDesigner;
import com.fr.design.form.util.FormDesignerUtils;
import com.fr.design.utils.ComponentUtils;
import com.fr.stable.Constants;
import com.fr.stable.GraphDrawHelper;

import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.event.MouseEvent;
import java.awt.geom.RoundRectangle2D;

public class FormSpacingLineDrawer {
    private static final Color LINE_COLOR = new Color(230, 82, 81);
    private static final Color TEXT_COLOR = new Color(255, 255, 255);
    private static final int TEXT_PADDING_HORIZONTAL = 8;
    private static final int TEXT_PADDING_VERTICAL = 2;
    private static final int MIN_SPACING = 10;
    private static final float TIP_FONT_SIZE = 10F;

    private FormDesigner designer;
    private XCreator hoverCreator = null;
    private XCreator selectedCreator = null;
    private Rectangle selectedRec;
    private Rectangle hoveredRec;
    private boolean isMouseMoveEvent = false;

    public FormSpacingLineDrawer(FormDesigner designer) {
        this.designer = designer;
    }

    public void updateMouseEvent(MouseEvent e, boolean isMouseMoveEvent) {
        selectedCreator = designer.getSelectionModel().getSelection().getSelectedCreator();
        if (selectedCreator != null) {
            this.hoverCreator = getHoverComponentAt(e.getX(), e.getY());
        }
        this.isMouseMoveEvent = isMouseMoveEvent;
    }

    public void draw(Graphics g) {
        if (!isMouseMoveEvent || selectedCreator == null || hoverCreator == null) {
            return;
        }

        if (!isDrawSpacingLine()) {
            return;
        }

        this.selectedRec = designer.getSelectionModel().getSelection().getRelativeBounds();
        this.hoveredRec = ComponentUtils.getRelativeBounds(hoverCreator);

        drawHorizontalSpacingLine(g);
        drawVerticalSpacingLine(g);
    }

    private void drawHorizontalSpacingLine(Graphics g) {
        AbstractFormParallelLine[] lines = getNearestHorizontalSide();
        drawSpacingLine(g, lines);
    }

    private void drawVerticalSpacingLine(Graphics g) {
        AbstractFormParallelLine[] lines = getNearestVerticalSide();
        drawSpacingLine(g, lines);
    }

    private void drawSpacingLine(Graphics g, int startX, int startY, int endX, int endY) {
        Graphics2D g2d = (Graphics2D) g.create();
        g2d.setColor(LINE_COLOR);
        GraphDrawHelper.drawLine(g2d, startX, startY, endX, endY, Constants.LINE_THIN);
    }

    private void drawSpacingLine(Graphics g, AbstractFormParallelLine[] nearestSides) {
        if (nearestSides.length != 2) {
            return;
        }
        int gap = nearestSides[0].getDistanceWithLine(nearestSides[1]);
        if (gap <= MIN_SPACING) {
            return;
        }

        int startX = (int) nearestSides[0].getStartPointOnVerticalCenterLine().getX() - designer.getHorizontalScaleValue();
        int startY = (int) nearestSides[0].getStartPointOnVerticalCenterLine().getY() - designer.getVerticalScaleValue();
        int endX = (int) nearestSides[0].getEndPointOnVerticalCenterLine(nearestSides[1].getParallelValue()).getX() - designer.getHorizontalScaleValue();
        int endY = (int) nearestSides[0].getEndPointOnVerticalCenterLine(nearestSides[1].getParallelValue()).getY() - designer.getVerticalScaleValue();

        drawSpacingLine(g, startX, startY, endX, endY);
        drawSpacingText(g, String.valueOf(gap), (startX + endX) / 2, (startY + endY) / 2);
        drawExtendedLine(g, nearestSides);
    }

    private void drawExtendedLine(Graphics g, int startX, int startY, int endX, int endY) {
        Graphics2D g2d = (Graphics2D) g.create();
        g2d.setColor(LINE_COLOR);
        GraphDrawHelper.drawLine(g2d, startX, startY, endX, endY, Constants.LINE_DASH);
    }

    private void drawExtendedLine(Graphics g, AbstractFormParallelLine[] nearestSides) {
        if (isNeedExtendedLine(nearestSides)) {
            int startX = (int) nearestSides[1].getExtendedLineStartPoint(nearestSides[0]).getX() - designer.getHorizontalScaleValue();
            int startY = (int) nearestSides[1].getExtendedLineStartPoint(nearestSides[0]).getY() - designer.getVerticalScaleValue();
            int endX = (int) nearestSides[1].getExtendedLineEndPoint(nearestSides[0]).getX() - designer.getHorizontalScaleValue();
            int endY = (int) nearestSides[1].getExtendedLineEndPoint(nearestSides[0]).getY() - designer.getVerticalScaleValue();
            drawExtendedLine(g, startX, startY, endX, endY);
        }
    }

    private void drawSpacingText(Graphics g, String text, int x, int y) {
        Graphics2D g2d = (Graphics2D) g.create();
        g2d.setColor(LINE_COLOR);
        Font newFont = g2d.getFont().deriveFont(TIP_FONT_SIZE).deriveFont(Font.BOLD);
        g2d.setFont(newFont);
        FontMetrics metrics = g2d.getFontMetrics();
        int lineHeight = metrics.getAscent(); // 这里由于都是数字，要居中必须忽略掉leading和descent的高度
        int lineWidth = metrics.stringWidth(text);

        int labelPaneX = x - lineWidth / 2 - TEXT_PADDING_HORIZONTAL;
        int labelPaneY = y - lineHeight / 2 - TEXT_PADDING_VERTICAL;
        int labelPaneWidth = lineWidth + 2 * TEXT_PADDING_HORIZONTAL;
        int labelPaneHeight = lineHeight + 2 * TEXT_PADDING_VERTICAL;
        int labelPaneArc = Math.min(labelPaneWidth, labelPaneHeight);
        GraphDrawHelper.fill(g2d, new RoundRectangle2D.Double(labelPaneX, labelPaneY, labelPaneWidth, labelPaneHeight, labelPaneArc, labelPaneArc));

        g2d.setColor(TEXT_COLOR);
        int labelX = x - lineWidth / 2;
        int labelY = y + (lineHeight - 2) / 2; // 由于ascent里面包含了一小段空白，数字又没有大写的情况，相当于五线行第一行是空的，所以往上微调一点来居中
        GraphDrawHelper.drawString(g2d, text, labelX, labelY);
    }

    private boolean isNeedExtendedLine(AbstractFormParallelLine[] nearestSides) {
        return nearestSides[0].isVerticalCenterLineBeforeTheParallelLine(nearestSides[1]) || nearestSides[0].isVerticalCenterLineBehindTheParallelLine(nearestSides[1]);
    }

    // 当前组件是否在参数面板里面
    private boolean isComponentInBody(XCreator creator) {
        XLayoutContainer container = XCreatorUtils.getHotspotContainer(creator);
        return container != null && !container.acceptType(XWParameterLayout.class);
    }

    private boolean isSelectedComponentInBody() {
        return isComponentInBody(selectedCreator);
    }

    private boolean isHoveredComponentInBody() {
        return isComponentInBody(hoverCreator);
    }

    private boolean isBodyAbsoluteLayout() {
        return !(designer instanceof FormParaDesigner) && FormDesignerUtils.isBodyAbsolute(designer);
    }

    private boolean isInAbsoluteLayout() {
        return isBodyAbsoluteLayout() && hoverCreator.isParentAbsolute() && selectedCreator.isParentAbsolute();
    }

    private boolean isDrawSpacingLine() {
        return isInAbsoluteLayout() && isSelectedComponentInBody() && isHoveredComponentInBody();
    }

    private AbstractFormParallelLine[] getNearestHorizontalSide() {
        AbstractFormParallelLine[] selectedRecSides = new AbstractFormParallelLine[] {
                new FormHorizontalParallelLine(selectedRec.y, selectedRec.x, selectedRec.x + selectedRec.width),
                new FormHorizontalParallelLine(selectedRec.y + selectedRec.height, selectedRec.x, selectedRec.x + selectedRec.width)
        };

        AbstractFormParallelLine[] hoveredCreatorSides = new AbstractFormParallelLine[] {
                new FormHorizontalParallelLine(hoveredRec.y, hoveredRec.x, hoveredRec.x + hoveredRec.width),
                new FormHorizontalParallelLine(hoveredRec.y + hoveredRec.height, hoveredRec.x, hoveredRec.x + hoveredRec.width)
        };
        return getNearestSide(selectedRecSides, hoveredCreatorSides);
    }

    private AbstractFormParallelLine[] getNearestVerticalSide() {
        AbstractFormParallelLine[] selectedRecSides = new AbstractFormParallelLine[] {
                new FormVerticalParallelLine(selectedRec.x, selectedRec.y, selectedRec.y + selectedRec.height),
                new FormVerticalParallelLine(selectedRec.x + selectedRec.width, selectedRec.y, selectedRec.y + selectedRec.height)
        };

        AbstractFormParallelLine[] hoveredCreatorSides = new AbstractFormParallelLine[] {
                new FormVerticalParallelLine(hoveredRec.x, hoveredRec.y, hoveredRec.y + hoveredRec.height),
                new FormVerticalParallelLine(hoveredRec.x + hoveredRec.width, hoveredRec.y, hoveredRec.y + hoveredRec.height)
        };
        return getNearestSide(selectedRecSides, hoveredCreatorSides);
    }

    private AbstractFormParallelLine[] getNearestSide(AbstractFormParallelLine[] lines1, AbstractFormParallelLine[] lines2) {
        AbstractFormParallelLine[] nearestSides = new AbstractFormParallelLine[] {lines1[0], lines2[0]};
        int minDistance = lines1[0].getDistanceWithLine(lines2[0]);
        for (int i = 0; i < lines1.length; i++) {
            for (int j = 0; j < lines2.length; j++) {
                int distance = lines1[i].getDistanceWithLine(lines2[j]);
                if (distance < minDistance) {
                    minDistance = distance;
                    nearestSides[0] = lines1[i];
                    nearestSides[1] = lines2[j];
                }
            }
        }
        return nearestSides;
    }

    private XCreator getHoverComponentAt(int x, int y) {
        XCreator component = designer.getComponentAt(x, y);
        XLayoutContainer parent = XCreatorUtils.getHotspotContainer(component).getTopLayout();
        if (parent != null) {
            if (!parent.isEditable()) {
                return parent;
            } else {
                if (parent == component) {
                    return null;
                }

                if (component instanceof XChartEditor || component instanceof XElementCase) {
                    return (XCreator) component.getParent();
                }
                return component;
            }
        } else {
            return component;
        }
    }
}